Ignition system for internal combustion engines



Aug. 7, 1945;

IGNITION SYS'IEM FOR INTERNAL-COMBUSTION ENGINES M. MALLQRY 2,381,61U

Filed Oct. 19 1944 A o VANCE INVENTOR. Mar/an Mafia/y Patented Aug. 7, 1945 IGNITION SYSTEM FOR INTERNAL-' COMBUSTION ENGINES Marion Mallory, Detroit, Mich.

8 Claims.

This invention relates to an ignition system for an internal combustion engine and more particularly to an ignition timer which is automatically controlled in accordance with the speed and load.

For smooth idling, an extreme retardation of the timing is necessary, .but upon a slight opening of the throttle, there should be an appreciable immediate advance of the timing. Following this, there should be a further gradual advance as the speed increases, but when the engine is working under full load with wide open throttle at either low or high speeds, it is desirable to retard the advance to some extent to prevent detonation.

This invention contemplates an ignition system for an internal combustion engine which will automatically time the spark as outlined above.

In pressure ignition systems the intake passageway pressures are used to actuate a suction device for controlling the timer. The suction device is connected with an orifice in the intake passageway on the atmosphere side of the throttle valve when the throttle is in idle position. As the throttle opens the orifice passes on to the engine side of the throttle valve. In all of these ignitioii systems wherein the manifold vacuum is used to advance the timer the problem has beenthat of getting a sufficient and early enough spark advance as the throttle opens from idle position. To make the spark advance early enough, in some instances the orifice has been positioned immediately adjacent to the throttle valve when in idle position so that the spark will immediately start to advance on the slightest opening movement of the throttle but when this is done the velocity is so high between the throttle valve and the orifice that the spark advances too much. As a matter of fact, the velocity of the motive fluid by the orifice when the throttle valve is only slightly open creates a vacuum at the orifice which is even higher than the manifold vacuum. To avoid too high spark advance when the throttle is only slightly opened, others have located this orifice somewhat above the throttle valve when closed to avoid the venturi or velocity effect but in such cases the spark advance comes in toolate, in other words the throttle must be open-,f ora considerable distance before the spark will be advanced and, as it is necessary to advancethe s'park immediately when the throttle isnbvedgaway ,from idle position to get the best "results, it is necessary to have the orifice set very ,close to the throttle.

Of course, as stated, in the usual pressure ignition system, if the orifice is set close to the throt- Application October 19, 1944, Serial No. 559,423

' to opening the throttle.

It is an object of my invention to produce an ignition system wherein the intake passageway vacuum is used to advance the spark at low engine speeds and as the throttle valve is moved only slightly open from idle position, and to avoid the vacuum created by the velocity between the throttle valve and the orifice from excessively advancing spark.

A further object is to cause the vacuum in the suction device to decrease more rapidly when the throttle is suddenly opened.

The first object is accomplished by utilizing the vacuum produced by the velocity between the throttle valve and the orifice to control a valve which controls communication between the suction device and the intake passageway on the engine side of the throttle valve.

The second object is accomplished by shutting off the communication between the suction device that advances and retards the spark and the intake manifold when the manifold vacuum drops to a predetermined point due to opening the throttle valve.

The drawing shows my ignition system.

The parts of my invention are as follows: intake passageway I, inlet opening 2, outlet to the engine 3, throttle valve 4, valve shaft 5, crank 6 fixed on the outer end of valve shaft 5, venturi l in the intake passageway I, suction device 8, flexible diaphragm 9, suction chamber ID, compression spring, timer cam l2, plate I3, circuit breaker l4 mounted on plate l3, rod I5 fixed at one end to diaphragm 9 and pivoted at the other end toplate I3, conduit I6 connecting suction chamber II] with branch conduit I'I leading to orifice ill in venturi I and with branch conduit l9 leading to orifice 2 0 in intake passageway I on the-engine side of valve 4, piston valve 2| in cylinder 22 for controlling communication between conduit l6 and orifice 20, compression spring 23 tending to keep valve 2| closed, orifice 24 positioned immediately adjacent to, and on the atmosphere side of, throttle valve 4 when in idle position, air bleed 25 for cylinder 22, and orifices 26 and 21.

The operation of my device is as follows: as-

suming throttle valve 4 is closed with orifice 24 on the atmosphere side of valve 4, spring 23 holds piston valve 2| over orifices 28 and 21 to thereby cut of! orifice 20 from conduit It. At this time the pressure in suction chamber III will be atmospheric and the distributor or timer will be in idle position, that is, retarded. If throttle 4 is moved toward open position, the high velocity of the motive fluid flowing by orifice 24 will create a vacuum in cylinder 22 thereby moving piston valve 2| toward the left, compressing spring 23 and placing orifices 26 and 21 in communication through circumferential groove 28 in spool valve 2| so that the intake manifold vacuum will act through orifice 20, conduits l9 and I8, suction chamber l0, flexible diaphragm 9, and rod l5 to rotate plate I 3 clockwise to advance the spark. However, this advance in the spark timing will not be as high as it would if orifice 24 were connected directly to conduit l8 and valve 2| eliminated.

If throttle 4 is moved wide open, then the vacuum at orifice 24 is substantially eliminated so that valve 2| moves toward the right, closing off orifice 20 from conduit It so that the suction device 8 is now influenced by the vacuum created by the velocity of the fluid flowing through venturi 1 past orifice I8. Thus, for wide open throttle or full load operation th ignition timing advance is controlled by the vacuum created by the motive fluid flowing through venturi 1 past orifice l8 and for part throttle or load operation the ignition timing is controlled by the intake passageway suction at orifice 20 as bled down through orifice l8 and passageway H.

In the event throttle valve 4 is moved slightly past orifice 24 the full manifold vacuum force -will.be on the diaphragm 9 which will give considerable spark advance and, if the throttle is opened further to cause a further drop in the manifold vacuum, spring 23 will move piston to' the right causing the manifold vacuum to be shut off from the suction device and the spark will be retarded to prevent spark knocks on acceleration when the throttle is moved only a short distance, so it can be seen that the spring 22 is the main control or varying factor of the vacuum forces in the suction device instead of the throttle 4.

I claim:

1. In an internalcombustion engine having an intake passageway and a throttle valve controlling the fiow of motive fluid through the passageway, the combination of an ignition timer, a suction device for controlling said ignition timer, an

orifice positioned in the intake passageway on the valve means controlling communication between the suction device and the second orifice, said valve means shutting off communication between the second orifice and the suction device when the throttle valve is in idle position and responding to the suction created by the fiuid flow by the third orifice as the throttle valve opens from idle position to place the second orifice in communication with the suction chamber of said tuated to advance the spark.

2. In an internal combustion engine having an intake passageway and a throttle valve controlling the flow of motive fluid through the passageway, the combination of an ignition timer, a suction device for controlling said ignition timer, an orifice positioned in the intake passageway on the atmosphere side of the throttle valve in all positions of the throttle valve, a second orifice positioned in the intake passageway on the engine side of the throttle valve in all positions of the throttle valve, conduits connecting the first and second orifices with the suction device and with each other, a third orifice in the intake passageway positioned immediately adjacent to and on the atmosphere side of the throttle valve when closed for idle, a cylinder communicating with said third orifice, a, valve in said cylinder controlling communication between the second orifice and the suction device and-between the second orifice and the first orifice, said valve being closed when the throttle valve is in idle position and responding to the suction created by the fluid flow by the third orifice as the throttle valve opens from idle position to place the second orifice in communication with the first orifice and the section device whereby the suction device responds to the suction in the intake passageway and actuates the ignition timer to advance the spark.

3. In an internal combustion engine having an intake passageway and a throttle valve controlling the fiow of motive fluid through the passageway, the combination of an ignition timer, a suction device for controlling said ignition timer. a venturi in the intake passageway positioned on the atmosphere side of the throttle, an orifice positioned in the venturi, a, second orifice positioned in the intake passageway on the en-- gine side of the throttle valve in all positions said orifices with the suction device, a third orifice in the intake passageway positioned adjacent to and on the atmosphere side of the throttle valve when in idle position, and suction responsive valve means controlling communication between the suction device and the second orifice, said valve means shutting off communication between the second orifice and the suction device when the throttle valve is in idle position and responding to the suction created by the fluid fiow by the third orifice as the throttle valve opens from idle position to place the second ori fice in communication with the suction chamber of said suction device whereby the ignition timer is actuated to advance the spark.

4. In an internal combustion engine having an intake passageway and a throttle valve controlling the fiow of motive fiuid through the passageway, the combination of an ignition timer, a

suction device for controlling said ignition timer, a venturi in the intake passageway positioned on fice and the suction device and between the second orifice and the first orifice, said valve being closed when the throttle valve is in idle position and responding to the suction created by the fluid fiow by the third orifice as the throttle valve opens from idle position to place the second orifice in communication with the first orifice and the suction device whereby the suction device responds to the suction in the intake passageway and actuates the ignition timer to advance the spark. i

5. In an internal combustion engine having an intake passageway and a throttle valve controlling the fiow of motive fluid through the passageway, the combination of an ignition timer, a suction device for controlling said ignition timer, an orifice positioned in the intake passageway on the atmosphere side of the throttle valve in all positions of the throttle valve, a second orifice positioned in the intake passageway on the engine side of the throttle valve in all positions of the throttle valve, conduitsconnecting the said orifices with the suction device; a third orifice in the intake passageway positioned adjacent to and on the atmosphere side of the throttle valve when closed for idle, a cylinder communicating with said third orifice and connected into the conduit between the second orifice and the suction device, a piston valve in. said cylinder closing off the conduit between the second orifice and the suction device when the throttle valve is in idle position, said piston valve responding to the suction created by the fluid flow by the third orifice as the throttle valve immediately opens from idle position to place the second orifice in communictaion with the suction device whereby the ignition timer is actuated to advance the spark.

6. In an internal combustion engine having an intake passageway and a throttle valve control-- ling the fiow of motive fluid through the passageway, the combination of an ignition timer, a suction device for controlling said ignition timer, a venturi in the intake, passageway positioned on the atmosphere side of the throttle,

an orifice positioned in,th e venturi, a second ori fice positioned in the intake passageway on the engine side of the throttle valve in all positions of the throttle valve, conduits connecting the said orifices with the suction device, a third orifice in the intake passageway positioned adjacent to and on the atmosphere side of the throttle valve when closed for idle, a cylinder communicating with said third orifice and connected into the conduit between the second orifice and the suction device, a piston valve in said cylinder closing oi! the conduit between the second orifice and the suction device when the. throttle valve is in idle position, said piston valve respond.- ing to the suction created by the fluid flow by the third orifice as the throttle valve immediately opens from idleposltlon to place the second oriflce incommunication with the suction device whereby the ignition timer is actuated to advance the spark.

7. In an internal combustion engine having an intake passageway and a throttle valve controlling the fiow of motive fluid through the passageway, the combination of an ignition timer, a suction device for controlling said ignition timer, an orifice positioned in the intake passageway on the engine side of, the throttle valve in all positions of the throttle valve, a conduit connecting the orifice with the suction device, a second orifice in the intake passageway positioned adjacent to and on the atmosphere side of the throttle valve when closed for idle, said second orifice passing on to the engine side of the throttle valve during the initial opening movement of the throttle valve, and suction responsive valve means controlling communication between the suction device and the first orifice, said valve means shutting off communication between the first orifice and the suction device when the throttle valve is in idle position and responding to the suction created by the fluid flow by the second orifice immediately as the throttle valve opens from idle position to thereby place the first orifice in communication with the suction chamber of the suction device whereby the ignition timer is actuated to advance the spark.

8. In an internal combustion engine having an intake passageway and a throttle valve controlling the flow of motive fluid through the passageway, the combination of an ignition timer, a suction device for controlling said ignition timer, a venturi in the intake passageway positioned on the atmosphere side of the throttle, an orifice positioned in the venturi, a second orifice positioned in the intake passageway on the engine side of the throttle valve in all positions of the throttle valve, conduits connecting the said orifices with the suction device, a third orifice in the intake passageway positioned adjacent to and on the atmosphere side of the throttle valve when closed for idle, a cylinder communicating with said thirdorifice and connected into the conduit between the second orifice and the suction device, a piston valve in said cylinder closing ofi the conduit between the second orifice and the suction device when the throttle valve is in idle position, said piston valve responding to the suction created by 60 motive fluid flowing through the venturi to control the spark advance.

' MARICN MALLORY. 

